Thanks to a loophole in property ownership, this alleyway has become a cacophonous street gallery.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

Despite repeated attempts to make it work, this former mining town is now nothing but dust and memories.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

Dedicated to the history of the 1,000 nuclear missiles that once covered the Great Plains.

South Dakota's oldest operating brewery is housed inside a historic firehouse.

An entire city block built completely out of petrified wood.

A cemetery housing wild west legends in South Dakota.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

A six-ton, 12-foot-tall concrete prairie dog is touted as the largest in the world.

The ravine where Jesse James supposedly performed an impossible jump to evade capture.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

Once America's tallest structure, now a Baltimore landmark.

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

The only geyser in the state of Pennsylvania is caused by pressure from an abandoned coal mine outside of the ghost town Centralia.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

A terrific purveyor of natural history objects and curios.

A crumbling hospital from the 1850s on Roosevelt Island.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.